1. Technical Field
The present invention relates to a sensor chip, a detection device using the sensor chip, and a method of manufacturing the sensor chip.
2. Related Art
Recent years, demand for sensors used for medical diagnostics or inspections of food and drink has increased, and further, development of a sensor and a detection device small in size and capable of performing sensing at high speed has been demanded. In order to meet such demand, a variety of types of sensors such as a sensor using an electrochemical process have been studied. Among these sensors, sensors using surface plasmon resonance (SPR) have been receiving increasing attention on the ground of possibility of integration, low cost, and applicability in all measurement environments.
Due to the background described above, with a goal of improvement in sensor sensitivity, there has been proposed a sensor utilizing localized surface plasmon resonance (LSPR) using fine metal particles or a fine metal particles. For example, there is a sensor for detecting a variation in medium in the vicinity of a fine metal particle to thereby detect adsorption or deposition of a target substance (detection target substance) by irradiating a transparent substrate having the fine metal particles fixed on the surface to form a film with a light and then measuring the absorbance of the light transmitted through the fine metal particles (see, e.g., JP-A-2000-356587 (Document 1)).
In Document 1 mentioned above, it is difficult to manufacture the fine metal particles so as to have a uniform size (dimension and shape), and to regularly arrange the fine metal particles. If the sizes and the arrangement of the fine metal particles fail to be controlled, variations are also caused in absorption and resonant wavelength generated by the surface plasmon resonance. Thus, it results that the width of the absorbance spectrum is broadened, and the peak intensity is decreased. Therefore, the signal variation for detecting the variation in the medium in the vicinity of the fine metal particle is low, and the improvement in the sensor sensitivity is limited.